a&p ch 7

What is the purpose of the dens (odontoid process)? It allows the head to nod back and forth. It allows the head to swivel from side to side. It balances the skull on top of the vertebral column. It is an attachment point for ligaments.

It allows the head to swivel from side to side.

Parietal bones (2 bones):

Join together at the top of the head to form the top and sides of the cranial cavity.

coronal suture

the joint between the parietal bones and the frontal bone

sagittal

the joint between the right and left parietal bone

The distal end of the fibula forms

the lateral malleolus of the ankle.

lambdoidal suture

the line of articulation between the parietal and occipital bone

costal margins

the lower edges of the thoracic cage, the two meet at the xiphoid process forming the costal angle which should be 90 degrees

pubis

the most anterior portion that joins with the other pubis at the symphysis pubis which is a disc of cartilage tht separates the two pubic bones

Five metacarpal bones form

the palm of the hand.

The phalanges are identified by

the Roman numerals I through V (beginning with the thumb) and as being proximal, middle, or distal

Key landmarks of the pectoral girdle (or shoulder girdle) include:

the acromion process, which is an extension of the scapula that articulates with the clavicle; the coracoid process, which provides a point of attachment for some of the muscles of the arm; and the glenoid cavity, which is a shallow socket that articulates with the head of the humerus.

Sudden, intense pressure on the intervertebral discs (such as may occur from lifting a heavy object) can cause

the annulus of the disc to crack. When this happens, the nucleus pulposus oozes out from the center of the disc and presses on the spinal cord or a spinal nerve, causing pain. This is called a herniated disc.

The lower edges of the thoracic cage are called

the costal margins; the two costal margins meet at the xiphoid process, forming the costal angle.

Named for the bones in which they reside

the frontal, maxillary, and ethmoid sinuses have well-defined shapes, whereas the sphenoid sinuses are like sinus cells, having a honey-combed shape.

The knuckles that appear when you clench your fist are

the heads of the metacarpals.

Eight carpal bones (two rows of four bones) form the

wrist. These bones allow the wrist to move back and forth and side to side. Each bone has a name.

body (the longest portion; it joins the manubrium at the sternal angle

—also called the angle of Louis—and provides the location of the second rib;

Styloid process

(an attachment point for several neck muscles)

Zygomatic arch

(cheekbone)

manubrium of the sternum

(the broadest portion),

how many thoracic vertebrae

12 t1-t12

how many coccyx vertebrae

4 fused

how many lumbar vertebrae

5 L1-L5

how many sacrum vertebrae

5 fused

Vertebral foramen:

An opening that allows for passage of the spinal cord

Palatine bones (two bones)

Form the posterior portion of the hard palate, part of the wall of the nasal cavity, and part of the floor of the orbit

The head of the fibula

articulates with the tibia

The axis (C2)

has a projection called the dens, or odontoid process. The dens projects into the atlas and allows the head to swivel from side to side (such as when saying "no").

The pectoral girdle (or shoulder girdle)

supports the arm; it consists of a clavicle (collarbone) and a scapula (shoulder blade).

The second-largest tarsal bone is the

talus. It articulates with three bones: the calcaneus on its inferior surface, the tibia on its superior surface, and another tarsal bone (called the navicular) on its anterior surface.

The proximal end of each carpal bone is called

the base, the shaft is called the body, and the distal end is called the head.

The normal curvatures of the spine are

the cervical curve, thoracic curve, lumbar curve, and sacral curve.

The thoracic cage consists of

the thoracic vertebrae, the ribs, and the sternum; these bones surround and protect the heart and lungs, and provide an attachment point for the pectoral girdle (shoulder) and upper limbs.

xiphoid process of the sternum

(provides an attachment point for some abdominal muscles and is an important landmark for CPR

how many cervical vertebrae

7 c1-c7

The vertebral column consists of 5 main sections:

7 cervical vertebrae, 12 thoracic vertebrae, 5 lumbar vertebrae, the sacrum (which consists of 5 fused vertebrae), and the coccyx (which consists of 4 fused vertebrae).

Acetabulum:

A depression that houses the head of the femur to form the "hip socket"

Mandible (1 bone):

Articulates with the temporal bone at the temporomandibular joint (TMJ), making it the only facial bone that can move; it is the largest and strongest bone of the face

Other bones associated with the skull:

Auditory ossicles (malleus, incus, stapes) and hyoid bone

Appendicular skeleton:

Bones of the limbs, pelvic, and shoulder areas

Maxillae (2 bones):

Meet to form the upper jaw; foundation of the face and every other facial bone (except for the mandible) articulates with the maxillae; the maxillae form part of the floor of the orbits, part of the roof of the mouth, and part of the floor and walls of the nose

Temporal bones (2 bones):

Form the sides of the cranium and part of the cranial floor; also contain the structures of the inner and middle ear, including the: External auditory meatus (an opening into the ear) Mastoid process (a prominent lump behind the ear)

Frontal bone (1 bone):

Forms the forehead and the roof of the eye sockets (orbits).

Obturator foramen:

Large hole below the acetabulum that is closed by a ligament

Iliac crest:

The upper, outer edge of the ilium

Body of the vertebrae

The weight-bearing portion of the vertebra

Structural characteristics of vertebrae differ slightly depending on location. Regardless, all vertebrae have a number of characteristics in common:

Vertebral foramen: An opening that allows for passage of the spinal cord Body: The weight-bearing portion of the vertebra Spinous process: Projects posteriorly from the vertebra (The spinous processes are the bumps you feel when you run your hand along the spine.) Transverse processes: Extend from each side of the vertebra; both the transverse and spinous processes serve as attachment points for muscles and ligaments

The head of the femur fits into the rounded contour of the

acetabulum.

To form the hip joint, the head of the femur rests in the: ilium. ischium. obturator foramen. acetabulum.

acetabulum.

false ribs

attached to cartilage

true ribs

attached to sternum by a strip of hyaline cartilage

The tarsal bones

comprise the ankle.

The medial and lateral epicondyles are the widest points of the

femur at the knee.

Four pairs of sinuses filled with air open into the

internal nose; they lighten the skull and act as resonators for sound production.

The radius

is one of the two bones of the lower arm; it is located on the same side as the thumb.

The humerus

is the long bone of the arm. The enlarged end of the humerus is called the head. Covered with articular cartilage, it articulates with the glenoid cavity of the scapula. A depression on the posterior side of the humerus called the olecranon fossa accommodates the olecranon process of the ulna when the arm is extended.

The femur

is the longest and strongest bone in the body. It articulates with the acetabulum of the pelvis to form a ball-and-socket joint. The head of the femur fits into the rounded contour of the acetabulum. The neck of the femur is a frequent site for fractures in elderly persons. Greater and lesser trochanter provide attachment points for hip muscles. The medial and lateral epicondyles are the widest points of the femur at the knee.

The ulna

is the other bone of the lower arm; it is longer than the radius.

The atlas (C1) has no body;

it consists of a delicate ring and a large vertebral foramen. Depressions on each side of the vertebra articulate with bony projections from the occipital bone of the skull. When the head moves back and forth (such as when nodding "yes"), the projections rock back and forth in these depressions.

The combination of the os coxae and the sacrum is known as the

pelvis. Because the marrow contained in the ilium produces blood cells, it is a common site for bone marrow biopsies.

The fingers are formed by bones called

phalanges.

costal angle may increase during

pregnancy, and lung disease called emphysema

Nasal bones (2 rectangular bones):

rectangular bones form the bridge of the nose (the rest of the nose is shaped by cartilage)

squamous suture

runs along the top edges of the temporal bone

The tibial tuberosity (palpable just below the patella)

serves as the attachment point for thigh muscles.

Vomer (1 bone):

small bone forms the inferior half of the nasal septum (the superior half is formed by the perpendicular plate of the ethmoid bone)

four pairs of sinuses which are named for the bones in which they reside

sphenoid, frontal, ethmoid, and maxillary

The pelvic girdle consists of

three bones fused together: the ilium (a large, flaring section you can feel under the skin), the ischium (the lower, posterior portion), and the pubis (the most anterior portion that joins with the other pubis at the symphysis pubis; a disc of cartilage separates the two pubic bones). Posteriorly, each os coxae articulates with the sacrum at the sacroiliac joint.

The thumb contains

two phalanges; the rest of the fingers contain three.

hyoid bone

u shaped bone that sits between the chin and larynx, the only bone that is NOT articulate with any other bone, and serves as an attachment point for muscles that control the tongue, mandible, and larynx

Axial skeleton:

Central, supporting axis

Inferior nasal conchae (2 bones):

Contribute to the nasal cavity

Ethmoid bone (1 bone):

Contributes to the walls of the orbits, the roof and walls of the nasal cavity, and the nasal septum. It lies anterior to the sphenoid bone; the cribriform plate (which forms part of the roof of the nasal cavity) lies on top. Tiny perforations in the cribriform plate allow branches of olfactory nerve to reach the brain. (important)

floating ribs

DO NOT attach to any part of the anterior thoracic cage

Transverse processes:

Extend from each side of the vertebra; both the transverse and spinous processes serve as attachment points for muscles and ligaments

Which of the following is not one of the paranasal sinuses? Frontal Maxillary Occipital Sphenoid

Occipital

Lacrimal bones (2 bones):

Paper-thin bones that form part of the side wall of the orbit

Which bone is not part of the ox coxae? Pelvis Ilium Ischium Pubis

Pelvis

Greater sciatic notch:

Point through which the sciatic nerve passes on its path to the back of the thigh

Ischial spine:

Projection into the pelvic cavity

Spinous process:

Projects posteriorly from the vertebra (The spinous processes are the bumps you feel when you run your hand along the spine.)

The ribs are classified as follows:

Ribs 1 to 7 (true ribs) attach to the sternum by a strip of hyaline cartilage called costal cartilage. Ribs 8, 9, and 10 attach to the cartilage of rib 7; these ribs, as well as ribs 11 and 12, are called false ribs. Ribs 11 and 12 (floating ribs) do not attach to any part of the anterior thoracic cage.

sutures.

The bones of the skull join at immovable joints called which include the coronal, lambdoidal, squamous, and sagittal

Zygomatic bones (2 bones):

Shape the cheeks and outer edge of the orbit

The metatarsals

form the middle portion of the foot; they are numbered I through V, beginning medially.

The phalanges

form the toes. The great toe is called the hallux.

lafort fracture

fracture of the face

Adult skeleton

has 206 bones: the axial skeleton has 80 bones, and the appendicular skeleton has 126 bones.{AU: 74 + 126 = 200, not 206. Please review.<<<SEE CHANGE.>>} The surfaces of bones have surface markings (ridges, depressions, bumps, pores, and projections); these provide routes for blood vessels and nerves, surfaces for muscle attachment, and areas for joint formation. Note: The names of bone surface markings and the names of all the bones in the body are listed in separate tables in the textbook. Consider encouraging students to use flashcards to learn these terms.

The fibula

helps stabilize the ankle; it does not bear any weight.

Greater and lesser trochanter provide attachment points for

hip muscles.

The transverse ligament

holds the dens in place; this allows the head to swivel from side to side. Bony projections from the occipital bone rock back and forth on the depressions of the atlas, allowing the head to move back and forth. A hard blow to the top of the head can drive the dens through the foramen magnum and into the brainstem, resulting in sudden death.

The base of the skull contains a large opening

(foramen magnum) through which the spinal cord passes. When the brain is injured, it swells. Because the skull cannot expand to accommodate the swelling brain, pressure inside the cranium increases. If the swelling is severe, the pressure will force the brainstem down, through the foramen magnum. The restricted opening of the foramen magnum will constrict the brainstem, resulting in respiratory arrest and, usually, death. (An exception is an infant skull, in which the suture lines haven't yet fused.)

Sphenoid bone (1 bone):

Forms a key part of the cranial floor, as well as the floor and side walls of the orbits. With the appearance of a giant moth, the sphenoid bone lies behind and slightly above the nose and throat. It has an indented area called the sella turcica that houses the pituitary gland. (important)

Occipital bone (1 bone):

Forms the rear of the skull.

Ischial tuberosity:

Supports your body when you are sitting

Of the two bones in the lower leg, which one is the only one that bears weight. It articulates with the femur.

TIBIA

The largest tarsal bone is the

calcaneus. It forms the heel and bears much of the body's weight.

The most unique of all the vertebrae are the first two cervical vertebrae (C1 and C2),

called the atlas and the axis. The atlas (C1) has no body; it consists of a delicate ring and a large vertebral foramen. Depressions on each side of the vertebra articulate with bony projections from the occipital bone of the skull. When the head moves back and forth (such as when nodding "yes"), the projections rock back and forth in these depressions. The axis (C2) has a projection called the dens, or odontoid process. The dens projects into the atlas and allows the head to swivel from side to side (such as when saying "no").

In between each vertebra is an

intervertebral disc that is designed to support weight and absorb shock. It consists of a gel-like core, called the nucleus pulposus (important), and a ring of tough fibrocartilage, called the annulus fibrosus. (important)

The vertebral column

is a flexible structure consisting of 33 vertebrae; it holds the head and torso upright, serves as an attachment point for the legs, encases the spinal cord, and allows the body to bend forward, backward, and sideways.

The patella (kneecap)

is a triangular sesamoid bone embedded in the tendon of the knee. It consists of cartilage at birth and ossifies between the ages of 3 and 6 years.

Medial malleolus

is the bony knob on the inner ankle.

Cuneiforms

make up the second row of tarsal bones.

The sternum has three regions:

manubrium (the broadest portion), body (the longest portion; it joins the manubrium at the sternal angle—also called the angle of Louis—and provides the location of the second rib; xiphoid process (provides an attachment point for some abdominal muscles and is an important landmark for CPR.

Key landmarks of the os coxae (two large bones of the hips) or innominate bones

pelvic girdle Iliac crest: The upper, outer edge of the ilium Greater sciatic notch: Point through which the sciatic nerve passes on its path to the back of the thigh Acetabulum: A depression that houses the head of the femur to form the "hip socket" Ischial spine: Projection into the pelvic cavity Ischial tuberosity: Supports your body when you are sitting Obturator foramen: Large hole below the acetabulum that is closed by a ligament

Two large bones of the hip

—called os coxae, or innominate bones—form the pelvic girdle and are the foundation of the pelvis. The pelvic girdle consists of three bones fused together: the ilium (a large, flaring section you can feel under the skin), the ischium (the lower, posterior portion), and the pubis (the most anterior portion that joins with the other pubis at the symphysis pubis; a disc of cartilage separates the two pubic bones). Posteriorly, each os coxae articulates with the sacrum at the sacroiliac joint.